Spaceflight Environment.

The safety and health of individuals who may be exposed to the spaceflight environment are first and foremost cared for through prevention. This environment, which encompasses microgravity, radiation, and alternobaric factors, can have physiologic impacts on every human system. Available medical care and resources in the spaceflight environment are currently limited by mass and volume constraints, with available medical resources thereby focusing on a patient's stabilization and evacuation. An understanding of the spaceflight environment and its possible effects is crucial for the treatment of individuals prior to, during, and after spaceflight.

Use of Esmarch bandage does not increase peripheral vein size in healthy volunteers: A randomized clinical trial.

INTRODUCTION: Ultrasound is used for peripheral intravenous (PIV) cannulation in patients with difficult landmark-guided IV access in the Emergency Department. Distal-to-proximal application of an Esmarch bandage on the target limb has been suggested as a method for increasing vein size and ease of cannulation. METHODS: This study was a single-blinded crossover randomized controlled trial comparing basilic vein size under ultrasound with use of an Esmarch bandage in addition to standard IV tourniquet ("tourniquet + Esmarch") compared to use of a standard IV tourniquet alone. Participant discomfort with the tourniquet + Esmarch was also compared to that with standard IV tourniquet alone. RESULTS: Twenty-two healthy volunteers were used to measure basilic vein size with and without the Esmarch bandage. There was no difference in basilic vein size between the two groups, with a mean diameter of 6.0 ± 1.5 mm in the tourniquet + Esmarch group and 6.0 ± 1.4 mm in the control group, p = 0.89. Discomfort score (from 0 to 10) was different between the groups, with a mean discomfort score of 2.1 in the tourniquet + Esmarch group and 1.1 in the standard IV tourniquet alone group (p < 0.001). CONCLUSIONS: This study showed that the use of an Esmarch bandage does not increase basilic vein size in healthy volunteers but is associated with a mild increase in discomfort.

Changes in harm reduction service providers professional quality of life during dual public health emergencies in Canada.

BACKGROUND: Harm reduction (HR) is a critical response to the pronounced toxicity deaths being experienced in Canada. HR providers report many benefits of their jobs, but also encounter chronic stress from structural inequities and exposure to trauma and death. This research study sought to quantify the emotional toll the toxicity emergency placed on HR providers (Cycle One; 2019). Study objectives were later expanded to determine the impact of the ongoing toxicity as well as the pandemic's impact on well-being (Cycle Two; 2021). METHODS: Standardized measures of job satisfaction, burnout, secondary traumatic stress, and vulnerability to grief were used in an online national survey. Open-ended questions addressed resources and supports. HR partners across Canada validated the findings and contributed to alternative interpretations and implications. RESULTS: 651 respondents in Cycle One and 1,360 in Cycle Two reported moderately high levels of job satisfaction; they reported finding great meaning in their work. Yet, mean levels of burnout and secondary traumatic stress were moderate, with the latter significantly increasing in Cycle Two. Reported vulnerability to grief was moderate but increased significantly during COVID. When available, supports lacked the quality necessary to respond to the complexities of HR workers' experiences, or an insufficient number of sessions were covered through benefits. Respondents shared that their professional quality of life was affected more by policy failures and gaps in the healthcare system than it was by the demands of their jobs. CONCLUSION: Both the benefits and the strain of providing harm reduction services cannot be underestimated. For HR providers, these impacts are compounded by the drug toxicity emergency, making the service gaps experienced by them all the more critical to address. Implications highlight the need for integration of HR into the healthcare system, sustainable and reliable funding, sufficient counselling supports, and equitable staffing models. Support for this essential workforce is critical to ensuring the well-being of themselves, the individuals they serve, and the health of the broader healthcare system.

Acute Appendicitis Treatment Strategies and Mortality Based on Critical Illness on Admission: An Observational Study.

Background: Trials have shown non-inferiority of non-operative management (NOM) for appendicitis, although critically ill patients have been often excluded. The purpose of this study is to evaluate surgical versus NOM outcomes in critically ill patients with appendicitis by measuring mortality and hospital length of stay (LOS). Patients and Methods: The Healthcare Cost and Utilization Project's (HCUP) Database was utilized to analyze data from 10 states between 2008 and 2015. All patients with acute appendicitis by International Classification of Diseases, Ninth Revision (ICD-9) codes over the age of 18 were included. Negative binomial and logistic regression were used to determine the association of acute renal failure (ARF), cardiovascular failure (CVF), pulmonary failure (PF), and sepsis by treatment strategy (laparoscopic, open, both, or no surgery) on mortality and hospital LOS. Results: Among 464,123 patients, 67.5%, 23.3%, 8.2%, and 0.8% underwent laparoscopic, open, NOM, or both laparoscopic and open surgery, respectively. Patients who underwent surgery had 58% lower odds of mortality and 34% shorter hospital LOS compared with NOM patients. Patients with ARF, CVF, PF, and sepsis had 102%, 383%, 475%, and 666% higher odds of mortality and a 47%, 46%, 71%, and 163% longer hospital LOS, respectively, compared with patients without these diagnoses on admission. Conclusions: Critical illness on admission increases mortality and hospital LOS. Patients who underwent laparoscopic, and to a lesser extent, open appendectomy had improved mortality compared with those who did not undergo surgery regardless of critical illness status.

57-Year-Old Male Veteran with Recurrent Fevers.

A 57-year-old male veteran presented to the emergency department for recurrent fevers for 10 days. The patient was febrile but had an overall benign physical exam. This interesting case explores the broad differential diagnosis and evaluation in a patient who presents with fever of unknown origin.

POCUS for Diastolic Dysfunction: A Review of the Literature.

Emergency and critical care physicians frequently encounter patients presenting with dyspnea and normal left ventricular systolic function who may benefit from early diastolic evaluation to determine acute patient management. The current American Society of Echocardiography Guidelines approach to diastolic evaluation is often impractical for point of care ultrasound (POCUS) evaluation, and few studies have evaluated the potential use of a simplified approach. This article reviews the literature on the use of a simplified diastolic evaluation to assist in determining acute patient management.

Mixed-Model Curriculum for Nerve Block Education in Emergency Medicine Residency.

Introduction With the rising opioid epidemic, there has been a push for multimodal pain management within the emergency department. Nerve blocks have been shown to be an effective pain management strategy for many conditions, with improved success when used with ultrasound. However, there is no generally accepted method for teaching residents how to perform nerve blocks. Materials and methods Seventeen residents from a single academic center were enrolled. The residents were surveyed pre-intervention regarding demographics, confidence, and use of nerve blocks. The residents then completed a mixed-model curriculum that included an electronic module (e-module) on three plane nerve blocks and a practice session. Three months later, residents were tested on their ability to independently perform the nerve blocks and resurveyed regarding confidence and use. Results Of the 56 residents in the program, 17 enrolled in the study; 16 participated in the first session, and nine participated in the second session. Each resident had < four ultrasound-guided nerve blocks prior to participation with a slight increase in the total number of nerve blocks after the sessions. Residents were able to perform, on average, 4.8 of seven tasks independently. Residents who completed the study reported feeling more confident in their ability to perform ultrasound-guided nerve blocks (p = 0.01) and to complete associated tasks (p < 0.01). Conclusion This educational model resulted in residents completing the majority of tasks independently with improved confidence in ultrasound-guided nerve blocks. There was only a slight increase in clinically performed blocks.

Ultrasound in Pregnancy.

This article reviews the use of ultrasound in pregnancy pertinent to the emergency physician. The techniques for transabdominal and transvaginal studies are detailed including approaches to gestational dating. Diagnosis of ectopic pregnancy is reviewed focusing on the potential pitfalls: reliance on beta-human chorionic gonadotropin, pseudogestational sac, interstitial pregnancy, and heterotopic pregnancy. Techniques for the identification of placental issues and presenting parts during the second and third trimesters are reviewed. Ultrasound is a safe and effective tool for the experienced emergency physician and is integral to providing high-quality care to pregnant women.

First Impressions Matter: Immune Imprinting and Antibody Cross-Reactivity in Influenza and SARS-CoV-2.

Many rigorous studies have shown that early childhood infections leave a lasting imprint on the immune system. The understanding of this phenomenon has expanded significantly since 1960, when Dr. Thomas Francis Jr first coined the term "original antigenic sin", to account for all previous pathogen exposures, rather than only the first. Now more commonly referred to as "immune imprinting", this effect most often focuses on how memory B-cell responses are shaped by prior antigen exposure, and the resultant antibodies produced after subsequent exposure to antigenically similar pathogens. Although imprinting was originally observed within the context of influenza viral infection, it has since been applied to the pandemic coronavirus SARS-CoV-2. To fully comprehend how imprinting affects the evolution of antibody responses, it is necessary to compare responses elicited by pathogenic strains that are both antigenically similar and dissimilar to strains encountered previously. To accomplish this, we must be able to measure the antigenic distance between strains, which can be easily accomplished using data from multidimensional immunological assays. The knowledge of imprinting, combined with antigenic distance measures, may allow for improvements in vaccine design and development for both influenza and SARS-CoV-2 viruses.

Re-Aiming Equity Evaluation in Clinical Decision Support: A Scoping Review of Equity Assessments in Surgical Decision Support Systems.

OBJECTIVE: We critically evaluated the surgical literature to explore the prevalence and describe how equity assessments occur when using clinical decision support systems. BACKGROUND: Clinical decision support (CDS) systems are increasingly used to facilitate surgical care delivery. Despite formal recommendations to do so, equity evaluations are not routinely performed on CDS systems and underrepresented populations are at risk of harm and further health disparities. We explored surgical literature to determine frequency and rigor of CDS equity assessments and offer recommendations to improve CDS equity by appending existing frameworks. METHODS: We performed a scoping review up to Augus 25, 2021 using PubMed and Google Scholar for the following search terms: clinical decision support, implementation, RE-AIM, Proctor, Proctor's framework, equity, trauma, surgery, surgical. We identified 1415 citations and 229 abstracts met criteria for review. A total of 84 underwent full review after 145 were excluded if they did not assess outcomes of an electronic CDS tool or have a surgical use case. RESULTS: Only 6% (5/84) of surgical CDS systems reported equity analyses, suggesting that current methods for optimizing equity in surgical CDS are inadequate. We propose revising the RE-AIM framework to include an Equity element (RE 2 -AIM) specifying that CDS foundational analyses and algorithms are performed or trained on balanced datasets with sociodemographic characteristics that accurately represent the CDS target population and are assessed by sensitivity analyses focused on vulnerable subpopulations. CONCLUSION: Current surgical CDS literature reports little with respect to equity. Revising the RE-AIM framework to include an Equity element (RE 2 -AIM) promotes the development and implementation of CDS systems that, at minimum, do not worsen healthcare disparities and possibly improve their generalizability.

Streptococcus oralis Employs Multiple Mechanisms of Salivary Mucin Binding That Differ Between Strains.

Streptococcus oralis is an oral commensal and opportunistic pathogen that can enter the bloodstream and cause bacteremia and infective endocarditis. Here, we investigated the mechanisms of S. oralis binding to oral mucins using clinical isolates, isogenic mutants and glycoconjugates. S. oralis bound to both MUC5B and MUC7, with a higher level of binding to MUC7. Mass spectrometry identified 128 glycans on MUC5B, MUC7 and the salivary agglutinin (SAG). MUC7/SAG contained a higher relative abundance of Lewis type structures, including Lewis b/y, sialyl-Lewis a/x and α2,3-linked sialic acid, compared to MUC5B. S. oralis subsp. oralis binding to MUC5B and MUC7/SAG was inhibited by Lewis b and Lacto-N-tetraose glycoconjugates. In addition, S. oralis binding to MUC7/SAG was inhibited by sialyl Lewis x. Binding was not inhibited by Lacto-N-fucopentaose, H type 2 and Lewis x conjugates. These data suggest that three distinct carbohydrate binding specificities are involved in S. oralis subsp. oralis binding to oral mucins and that the mechanisms of binding MUC5B and MUC7 differ. Efficient binding of S. oralis subsp. oralis to MUC5B and MUC7 required the gene encoding sortase A, suggesting that the adhesin(s) are LPXTG-containing surface protein(s). Further investigation demonstrated that one of these adhesins is the sialic acid binding protein AsaA.

Which Way Would You Slice It? Evaluation of 3 Educational Models for the Loop Drainage Technique.

Introduction: Emergency department visits for cutaneous abscesses are increasing. It is important for healthcare professionals to be proficient in identifying and treating abscesses. Loop drainage technique (LDT) is a newer technique which has been described in several articles but limited resources for teaching have been studied. The objective of this study was to compare 3 models for learning and teaching the LDT. Methods: This was a prospective survey study of a convenience sample of emergency medicine residents at a large urban academic center. Residents volunteered to participate during a scheduled cadaver and simulation session. After a self-directed review of the LDT, each participant performed ultrasound visualization and then the LDT on 3 simulated abscesses: a cadaveric model, a commercial abscess pad, and a homemade phantom. Participants completed pre- and post-simulation surveys. Results: Of 57 residents, 28 participated in the 1-day simulation. The majority (57.1%, p < 0.009) preferred the cadaver model for learning the LDT, and 78.6% reported it to have the most realistic physical examination for an abscess (p = 0.001). Prior to participation, 0% of residents felt proficient performing LDT. After participation, 46.4% of residents felt proficient and 78.6% reported intent to use in clinical practice (p < 0.001). Conclusions: Simulation is an effective educational tool for both learning new skills and improving procedural competency. Residents found cadavers provided the most realistic physical examination, and the majority preferred it for learning the LDT. However, cadavers are not always accessible, an important factor when considering various educational settings.

Metformin and Covid-19: Focused Review of Mechanisms and Current Literature Suggesting Benefit.

Metformin is the first-line medication for type 2 diabetes, but it also has a long history of improved outcomes in infectious diseases, such as influenza, hepatitis C, and in-vitro assays of zika. In the current Covid-19 pandemic, which has rapidly spread throughout the world, 4 observational studies have been published showing reduced mortality among individuals with home metformin use. There are several potential overlapping mechanisms by which metformin may reduce mortality from Covid-19. Metformin's past anti-infectious benefits have been both against the infectious agent directly, as well as by improving the underlying health of the human host. It is unknown if the lower mortality suggested by observational studies in patients infected with Covid-19 who are on home metformin is due to direct activity against the virus itself, improved host substrate, or both.

'Diagnosis of Boerhaave's Syndrome With Aid of Bedside Ultrasound.

BACKGROUND: Boerhaave's syndrome is characterized by transmural rupture of the distal esophagus in the setting of increased intraluminal pressures combined with negative intrathoracic pressure. It is a rare condition with high mortality (20-50% mortality rate). CASE REPORT: This is a case of a 47-year-old man who appeared acutely ill, presenting with shortness of breath, chest and abdominal pain, and diagnosed with Boerhaave's syndrome with the assistance of bedside ultrasound. WHY SHOULD AN EMERGENCY PHYSICIANS BE AWARE OF THIS?: Emergency physicians must have a heightened suspicion of this diagnosis in patients presenting with chest and abdominal pain and can use bedside ultrasound skills to aid with diagnosis.

Streptococcus pneumoniae pneumolysin and neuraminidase A convert high-density lipoproteins into pro-atherogenic particles.

High-density lipoproteins (HDLs) are a group of different subpopulations of sialylated particles that have an essential role in the reverse cholesterol transport (RCT) pathway. Importantly, changes in the protein and lipid composition of HDLs may lead to the formation of particles with reduced atheroprotective properties. Here, we show that Streptococcus pneumoniae pneumolysin (PLY) and neuraminidase A (NanA) impair HDL function by causing chemical and structural modifications of HDLs. The proteomic, lipidomic, cellular, and biochemical analysis revealed that PLY and NanA induce significant changes in sialic acid, protein, and lipid compositions of HDL. The modified HDL particles have reduced cholesterol acceptor potential from activated macrophages, elevated levels of malondialdehyde adducts, and show significantly increased complement activating capacity. These results suggest that accumulation of these modified HDL particles in the arterial intima may present a trigger for complement activation, inflammatory response, and thereby promote atherogenic disease progression.

Morbidity and Mortality Trends of Pancreatitis: An Observational Study.

Background: Pancreatitis accounts for more than $2.5 billion of healthcare costs and remains the most common gastrointestinal (GI) admission. Few contemporary studies have assessed temporal trends of incidence, complications, management, and outcomes for acute pancreatitis in hospitalized patients at the national level. Methods: We used data from one of the largest hospital-based databases available in the United States, the Healthcare Cost and Utilization Project's (HCUP) State Inpatient Database, from 10 states between 2008 and 2015. We included patients with a diagnosis of acute pancreatitis (ICD-9 CM 577.0). Patient- and hospital-level data were used to estimate incidence and inpatient mortality rates. Results: From 80,736,256 hospitalizations, 929,914 (1.15%) cases of acute pancreatitis were identified, 186,226 (20.2%) of which were caused by gallbladder disease). The median age was 53 years (interquartile range [IQR], 41-67) and 50.8% were men. In-hospital mortality was 2.5% and crude mortality rates declined from 2.9% to 2.0% over the study period. Admission year remained significant after adjusting for patient demographics and comorbidities (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.89-0.90; p < 0.001). Gallbladder disease was associated with decreased odds of mortality (OR, 0.60; 95% CI, 0.57-0.62). Median length of stay was four days (IQR, 2-7) and decreased over time. The rates of surgical and endoscopic interventions were highest in 2011 (peak incidence of 16.1% and 9.5%, respectively) and have been decreasing since. Surgical providers were, on average, more likely than medical providers to perform surgery in both those with and without gallbladder disease etiology (gallbladder disease OR, 7.11; 95% CI, 5.46-9.25; non-gallbladder disease OR, 20.50; 95% CI, 16.81-25.01), endoscopy (gallbladder disease OR, 1.22; 95% CI, 0.87-1.72; non-gallbladder disease OR, 1.60; 95% CI, 1.18-2.16), or both (gallbladder disease OR, 7.00; 95% CI, 5.22-9.37; non-gallbladder disease OR, 8.85; 95% CI, 5.61-13.96). Conclusions: The incidence of pancreatitis, from 2008 to 2015, has increased whereas inpatient mortality (i.e., case fatality) has decreased. Understanding temporal trends in outcomes and management along with provider, hospital, and regional variation can better identify areas for future research and collaboration in managing these patients.

Endothelial Heparan Sulfate Proteoglycans in Sepsis: The Role of the Glycocalyx.

There is increasing recognition of the importance of the endothelial glycocalyx and its in vivo manifestation, the endothelial surface layer, in vascular homeostasis. Heparan sulfate proteoglycans (HSPGs) are a major structural constituent of the endothelial glycocalyx and serve to regulate vascular permeability, microcirculatory tone, leukocyte and platelet adhesion, and hemostasis. During sepsis, endothelial HSPGs are shed through the induction of "sheddases" such as heparanase and matrix metalloproteinases, leading to loss of glycocalyx integrity and consequent vascular dysfunction. Less well recognized is that glycocalyx degradation releases HSPG fragments into the circulation, which can shape the systemic consequences of sepsis. In this review, we will discuss (1) the normal, homeostatic functions of HSPGs within the endothelial glycocalyx, (2) the pathological changes in HSPGs during sepsis and their consequences on the local vascular bed, and (3) the systemic consequences of HSPG degradation. In doing so, we will identify potential therapeutic targets to improve vascular function during sepsis as well as highlight key areas of uncertainty that require further mechanistic investigation.

Contribution of growth hormone secretagogue receptor (GHSR) signaling in the ventral tegmental area (VTA) to the regulation of social motivation in male mice.

Most psychiatric disorders are characterized by deficits in the ability to interact socially with others. Ghrelin, a hormone normally associated with the regulation of glucose utilization and appetite, is also implicated in the modulation of motivated behaviors including those associated with food and sex rewards. Here we hypothesized that deficits in ghrelin receptor (growth hormone secretagogue receptor; GHSR) signaling are also associated with deficits in social motivation in male mice. To test this hypothesis, we compared social motivation in male mice lacking GHSR or mice treated with the GHSR antagonist JMV2959 with that of WT or vehicle-treated mice. GHSR signaling in dopamine cells of the ventral tegmental area (VTA) has been implicated in the control of sexual behavior, thus we further hypothesized that GHSR signaling in the VTA is important for social motivation. Thus, we conducted studies where we delivered JMV2959 to block GHSR in the VTA of mice, and studies where we rescued the expression of GHSR in the VTA of GHSR knockout (KO) mice. Mice lacking GHSR or injected with JMV2959 peripherally for 3 consecutive days displayed lower social motivation as reflected by a longer latency to approach a novel conspecific and shorter interaction time compared to WT or vehicle-treated controls. Furthermore, intra-VTA infusion of JMV2959 resulted in longer latencies to approach a novel conspecific, whereas GHSR KO mice with partial rescue of the GHSR showed decreased latencies to begin a novel social interaction. Together, these data suggest that GHSR in the VTA facilitate social approach in male mice, and GHSR-signaling deficits within the VTA result in reduced motivation to interact socially.

Metformin and risk of mortality in patients hospitalised with COVID-19: a retrospective cohort analysis.

BACKGROUND: Type 2 diabetes and obesity, as states of chronic inflammation, are risk factors for severe COVID-19. Metformin has cytokine-reducing and sex-specific immunomodulatory effects. Our aim was to identify whether metformin reduced COVID-19-related mortality and whether sex-specific interactions exist. METHODS: In this retrospective cohort analysis, we assessed de-identified claims data from UnitedHealth Group (UHG)'s Clinical Discovery Claims Database. Patient data were eligible for inclusion if they were aged 18 years or older; had type 2 diabetes or obesity (defined based on claims); at least 6 months of continuous enrolment in 2019; and admission to hospital for COVID-19 confirmed by PCR, manual chart review by UHG, or reported from the hospital to UHG. The primary outcome was in-hospital mortality from COVID-19. The independent variable of interest was home metformin use, defined as more than 90 days of claims during the year before admission to hospital. Covariates were comorbidities, medications, demographics, and state. Heterogeneity of effect was assessed by sex. For the Cox proportional hazards, censoring was done on the basis of claims made after admission to hospital up to June 7, 2020, with a best outcome approach. Propensity-matched mixed-effects logistic regression was done, stratified by metformin use. FINDINGS: 6256 of the 15 380 individuals with pharmacy claims data from Jan 1 to June 7, 2020 were eligible for inclusion. 3302 (52·8%) of 6256 were women. Metformin use was not associated with significantly decreased mortality in the overall sample of men and women by either Cox proportional hazards stratified model (hazard ratio [HR] 0·887 [95% CI 0·782-1·008]) or propensity matching (odds ratio [OR] 0·912 [95% CI 0·777-1·071], p=0·15). Metformin was associated with decreased mortality in women by Cox proportional hazards (HR 0·785, 95% CI 0·650-0·951) and propensity matching (OR 0·759, 95% CI 0·601-0·960, p=0·021). There was no significant reduction in mortality among men (HR 0·957, 95% CI 0·82-1·14; p=0·689 by Cox proportional hazards). INTERPRETATION: Metformin was significantly associated with reduced mortality in women with obesity or type 2 diabetes who were admitted to hospital for COVID-19. Prospective studies are needed to understand mechanism and causality. If findings are reproducible, metformin could be widely distributed for prevention of COVID-19 mortality, because it is safe and inexpensive. FUNDING: National Heart, Lung, and Blood Institute; Agency for Healthcare Research and Quality; Patient-Centered Outcomes Research Institute; Minnesota Learning Health System Mentored Training Program, M Health Fairview Institutional Funds; National Center for Advancing Translational Sciences; and National Cancer Institute.